Warning Signs in Swatch Options

[Hosun]

Hi,

In Swatch Options, there are two warning signs (triangle and cube). 

Can I use the colors with those signs unchecked?

I want to use #ff0000 and #b3b3b3.

Hosun

Screenshot 1

Screenshot 2

 

[Monika Gause · Accepted solution]

Please do just ignore the web safe color warning (the cube). It's been outdated for 20 years.

As for the out of gamut warning: are you going to print these colors? In offset?

[Hosun]

Thank you (Monika and Bill) very much for your replies. 

I am asking that question, while making an EPUB. It's the reason why I chose the RGB mode. 
Taking into account your replies, I think I don't need to be binding to  the triangle symbol (out of gamut warning).

Hosun

[Bill Silbert · Accepted solution]

The triangle symbol merely means that you would not be able to match that color very well, if at all,  if you wanted to print it using 4 color process (CMYK). Any time you see that symbol it means that the color is outside the gamut of what is possible using process colors.